KR20040083361A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: An LCD is provided to form desired accumulation capacity even in the case of short circuit of pixel electrodes supplying charges to accumulation capacity forming patterns in pixels, thereby increasing the display quality. CONSTITUTION: An LCD includes an insulating substrate and its facing substrate, and a liquid crystal layer between the substrates. The insulating substrate has a plurality of pixels, wherein more than one pixel among the pixels has a pixel electrode(4) and a common electrode(5) inside respectively both electrodes facing each other. Accumulation capacity electrodes(3) are connected to the common electrodes. Scanning lines(1) are in parallel to the accumulation capacity electrodes approximately. Signal lines(2) intersects the scanning lines via an insulating film and supplies signals to the pixel electrodes. A pattern(12) for forming accumulation capacity is disposed with respect to the accumulation capacity electrodes via the insulating film and connected to the pixel electrodes. The pattern applies electric fields in a direction parallel to the insulating substrate between the pixel and common electrodes. The pixel electrodes has two or more electric charge supplying paths(13,14) toward the pattern.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix liquid crystal display device in which a display is applied by applying a voltage in a direction substantially parallel to a substrate between opposite electrodes.

Recently, in order to achieve high viewing angle of a liquid crystal display device, an electric field is applied in a direction substantially parallel to an insulating substrate between a pixel electrode and a common electrode arranged to face each other, and a liquid crystal is oriented to display (lateral electric field system). Adoption of the liquid crystal display device is advanced. By adopting the lateral electric field system, it becomes clear that the change in contrast and the inversion of the gradation level when the viewing direction is changed are almost eliminated. However, in the liquid crystal display device of the conventional lateral electric field system, the storage capacitor is connected to the pixel electrode in one pixel and formed in the storage capacitor formation pattern formed to form the storage capacitor with the storage capacitor electrode and the insulating film interposed therebetween. The potential was supplied to the formation pattern only through one potential supply path formed of the pixel electrode.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2000-131714 (Fig. 1)

[Patent Document 2] Japanese Unexamined Patent Publication No. 2001-33814 (FIG. 1)

However, in the prior art according to Patent Document 1, only one potential supply path is provided in the pixel electrode and the storage capacitor formation pattern formed in one or more pixels, and the pixel electrode and the storage capacitor are formed from the connection portion of the pixel electrode and the drain electrode. If the wiring of the pixel electrode to the connection portion of the pattern is disconnected due to the generation of foreign matter or the like during the manufacturing process, it is impossible to form a desired storage capacitor because no potential is supplied to the storage capacitor formation pattern. There was a problem that a defect such as blinking occurs.

On the other hand, in the prior art of the said patent document 2, although the example in which the pixel electrode and the storage capacitance formation pattern are formed with the same conductive film is disclosed, the pixel electrode formed in one or more pixels also accumulate | stores in this structure. In the capacitance formation pattern (accumulation capacitor portion in this publication), only one potential supply path is provided, and the connection portion between the pixel electrode and the drain electrode is connected to the pixel electrode and the accumulation capacitor formation pattern (accumulation capacitor portion). In the wiring of the pixel electrode, when disconnected due to the generation of foreign matter or the like in the manufacturing process, no potential is supplied to the pattern for forming the capacitance, which makes it impossible to form a desired accumulation capacitance, resulting in flickering of the screen, and the like. There was a problem of causing a defect.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. The present invention provides a liquid crystal display device having a high display quality by enabling a potential to be supplied to a storage capacitor formation pattern and forming a desired storage capacitor even when a disconnection of the pixel electrode occurs. For the purpose of

1 is a plan view of approximately one pixel of a liquid crystal display device in the first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a manufacturing process in each part of an A-A part to a D-D part in FIG. 1. FIG.

Explanation of symbols on the main parts of the drawings

1: scanning line 2: video signal line

3: storage capacitor electrode 4: pixel electrode

5: common electrode

6: contact hole for connecting pixel electrode 4 and storage capacitor formation pattern 12

7: contact hole for connecting common electrode 5 and storage capacitor electrode 3

8: contact hole for connecting pixel electrode 4 and drain electrode 11

9 thin film transistor 10 source electrode

11 drain electrode 12 pattern for forming storage capacitor

13: First potential supply path to storage capacitor formation pattern 12 in pixel electrode 4

14: second potential supply path to storage capacitor formation pattern 12 in pixel electrode 4

15 insulating substrate 16 gate insulating film

17 semiconductor film 18 contact film

19: insulating film

A liquid crystal display device according to the present invention includes a plurality of pixels formed on an insulating substrate, a pixel electrode formed in at least one of the plurality of pixels, and a pixel electrode formed in at least one of the plurality of pixels and disposed to face the pixel electrode. A common electrode, a storage capacitor electrode connected to the common electrode, a scan line formed substantially parallel to the storage capacitor electrode, an image signal line intersecting the scan line and the insulating film therebetween, and supplying a signal to the pixel electrode, the insulating substrate and the liquid crystal An opposing substrate opposed through the substrate; and a storage capacitor formation pattern connected to the pixel electrode while being disposed to form a storage capacitor with the storage capacitor electrode and the insulating film interposed therebetween, between the pixel electrode and the common electrode. Applying an electric field in a direction substantially parallel to the insulating substrate, A liquid crystal display device which displays by aligning a liquid crystal, wherein the pixel electrode has two or more potential supply paths to the storage capacitor formation pattern.

Embodiment of the invention

Embodiment 1

A first embodiment of the present invention will be described with reference to Figs. 1 is a plan view of approximately one pixel of a liquid crystal display device according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the manufacturing process in each part of the A-A part to the D-D part of FIG.

The liquid crystal display device which concerns on this invention is demonstrated by FIG. 1, referring the manufacturing process drawing of FIG. First, as shown in FIG. 2A, the insulating substrate 15 has light transmittance such as Cr, Al, Ti, Ta, Mo, W, Ni, Cu, Au, Ag, an alloy containing them as a main component, or ITO. A conductive film or a multilayer film thereof is formed by a sputtering method, a vapor deposition method, or the like, and is substantially parallel to the scanning line 1 and the scanning line 1 including the gate electrode of the thin film transistor 9 by photolithography and processing. The storage capacitor electrode 3 arranged is formed. Here, the storage capacitor electrode 3 is disposed at substantially the center of the wiring direction of the video signal line 2 described later in one pixel. By arranging this storage capacitor electrode, it becomes possible to prevent a short circuit between the scanning line 1 and the storage capacitor electrode 3. Next, as shown in FIG. 2B, the gate insulating film 16 made of silicon nitride or the like is formed, and in the case of the semiconductor film 17 made of amorphous Si or polycrystalline Si, and the n-type TFT, impurities such as P are highly concentrated. A contact film 18 made of doped n + amorphous Si or n + polycrystalline Si or the like is successively formed by, for example, plasma CVD, atmospheric CVD, and reduced pressure CVD. Thereafter, the semiconductor film 17 and the contact film 18 are patterned in island shapes in the required region.

Next, as shown in FIG. 2C, a conductive film having light transmissivity, such as Cr, Al, Ti, Ta, Mo, W, Ni, Cu, Au, Ag, an alloy containing them as a main component, or ITO, or a multilayer film thereof After the film is formed by the sputtering method or the vapor deposition method, the image signal line 2, the source electrode 10, the drain electrode 11, the storage capacitor formation pattern 12, and the like are formed by photolithography and microfabrication techniques. . Here, the storage capacitor formation pattern 12 is disposed so as to overlap with the storage capacitor electrode 3 at a substantially central portion in the wiring direction of the video signal line 2 in one pixel, and the storage capacitor is shown in FIGS. 1 and 2. As shown, it is formed between the storage capacitor formation pattern 12 disposed with the storage capacitor electrode 3 and the gate insulating film 16 interposed therebetween. In addition, the contact film 18 is etched using the source electrode 10 and the drain electrode 11 or the photoresist formed thereon as a mask, and the contact film 18 is removed from the channel region of the thin film transistor 9.

Next, as shown in Fig. 2D, an insulating film 19 made of silicon nitride, silicon oxide, an inorganic insulating film, an organic resin, or the like is formed into a film. Thereafter, contact holes 6, 7, 8 are formed by photolithography and etching which is a subsequent process. Here, the contact hole 6 connects the pixel electrode 4 and the storage capacitor formation pattern 12 to the contact hole, and the contact hole 7 connects the common electrode 5 and the storage capacitor electrode 3 to each other. The contact hole and the contact hole 8 represent a contact hole connecting the pixel electrode 4 and the drain electrode 11. On the other hand, the contact hole 6 which connects the pixel electrode 4 and the storage capacitor formation pattern 12 is formed in two places in the area | region in which the storage capacitor formation pattern 12 was formed. Therefore, the pixel electrode 4 and the storage capacitor formation pattern 12 are connected through the two contact holes. The thin film transistor 9 is formed on the insulating substrate 15 by the gate electrode, the source electrode 10, the drain electrode 11, the gate insulating film 16, the semiconductor film 17, the contact film 18, or the like. .

Finally, as shown in Fig. 2E, a conductive film having light transmissivity, such as Cr, Al, Ti, Ta, Mo, W, Ni, Cu, Au, Ag, an alloy containing them as a main component, or ITO, or a multilayer film thereof. After the film is formed, the pixel electrode 4 and the common electrode 5 are formed by patterning. Here, when the potential is supplied from the drain electrode 11 to the storage capacitor formation pattern 12 through the pixel electrode 4 when the pixel electrode 4 is formed, a plurality of potential supply paths are formed (in FIG. 1). 2), the pixel electrode 4 is divided into a first potential supply path 13 and a second potential supply path 14 to the storage capacitor formation pattern 12, thereby forming a storage capacitor formation pattern ( 12) The potential can be supplied to the structure. Therefore, the two potential supply paths 13 and 14 are formed between the connection portion of the storage capacitor formation pattern 12 and the pixel electrode 4 from the connection portion of the pixel electrode 4 and the drain electrode 11. have. In addition, the pixel electrode 4 and the common electrode 5 are disposed to face each other so that an electric field can be applied in a direction substantially parallel to the insulating substrate 15. In addition, in FIG. 1 and FIG. 2, the pixel electrode 4 and the common electrode 5 are formed with the conductive film of the same layer for the simplification of a manufacturing process.

A liquid crystal display device is manufactured by disposing an opposing substrate (not shown) on the insulating substrate formed as described above via a liquid crystal.

As described above, by forming two or more potential supply paths for the storage capacitor formation pattern in the pixel, even when any one of the potential supply paths is disconnected by foreign matter or the like in the manufacturing process, the potential can be supplied to the storage capacitor formation pattern. As a result, a desired storage capacitor can be formed to obtain a liquid crystal display device with high display quality.

In addition, in this embodiment, although the case where two potential supply path | routes to the storage capacitance formation pattern were formed from the drain electrode was demonstrated, it is not limited to this, Even if it is a plurality, such as three or four, the same effect is demonstrated. It is obvious that. In addition, in this embodiment, although the pixel electrode and the common electrode are formed from the same layer of conductive film, it is not limited to this, It can also form from a different conductive film. In this case, the storage capacitor formation pattern and the pixel electrode are formed of the same conductive film, and the contact holes of the storage capacitor formation pattern and the pixel electrode may be unnecessary. By forming a plurality of supply paths, the same effect can be obtained.

In the present embodiment, as shown in FIG. 1, the potential supply paths from the storage capacitor electrode to the common electrode are formed one by one in the upper and lower portions in one pixel with the storage capacitor electrode interposed therebetween. Alternatively, when both are disconnected, there is a problem that the potential supply of the upper or lower common electrode or the upper and lower common electrodes sandwiching the storage capacitor electrodes in one pixel is not sufficiently performed, and the desired potential is not supplied. Therefore, in order to form two storage capacitor electrodes up and down in one pixel with respect to the potential supply path from the storage capacitor electrode to the common electrode, for example, the storage capacitor electrode 3 may be formed in the region X in FIG. ) Forms a region where the accumulation capacitor formation pattern 12 is not formed, and It is set as the structure which forms the contact hole 7 of a positive electrode. This configuration makes it possible to stably perform potential supply from the storage capacitor electrode to the common electrode.

In addition, this invention is not limited to the layer structure of the above-mentioned embodiment, and the lamination order of each layer, It is applicable to all the liquid crystal display devices which have a pixel electrode which supplies an electric potential to the pattern for accumulation capacitance formation.

According to the present invention, a desired storage capacitance can be formed and a display device having high display quality can be obtained even when disconnection occurs in the pixel electrode supplying a potential to the storage capacitance formation pattern in the pixel.

Claims (4)

A plurality of pixels formed on the insulating substrate, A pixel electrode formed in at least one pixel of the plurality of pixels, A common electrode formed in at least one of the plurality of pixels and disposed to face the pixel electrode; A storage capacitor electrode connected to the common electrode, A scan line formed substantially parallel to the storage capacitor electrode, An image signal line intersecting the scan line and the insulating layer therebetween and supplying a signal to the pixel electrode; An opposing substrate facing the insulating substrate and the liquid crystal between them, and A storage capacitor formation pattern connected to the pixel electrode while being disposed to form a storage capacitor with the storage capacitor electrode and the insulating film interposed therebetween, A liquid crystal display device which applies an electric field in a direction substantially parallel to the insulating substrate between the pixel electrode and the common electrode and aligns the liquid crystal to perform display. And said pixel electrode has two or more potential supply paths to said storage capacitor formation pattern. The method of claim 1, A gate electrode connected to the scan line, A source electrode connected to the video signal line, and An additional drain electrode disposed to face the source electrode and connected to the pixel electrode; Two or more potential supply paths from the pixel electrode to the storage capacitor formation pattern are formed between a connection portion of the storage capacitor formation pattern and the pixel electrode from a connection portion of the pixel electrode and the drain electrode. Liquid crystal display. The storage capacitor according to claim 1 or 2, wherein the pixel electrode and the common electrode are formed of the same conductive film, and the pixel electrode is formed through the two or more contact holes formed in the insulating film on the storage capacitor formation pattern. It is connected with the pattern for formation, The liquid crystal display device characterized by the above-mentioned. The liquid crystal display device according to any one of claims 1 to 3, wherein the storage capacitor electrode and the storage capacitor formation pattern are disposed almost at the center in the wiring direction of the video signal line of the one pixel.